Bacterial skin infections occur when bacteria enter through the surface of the skin. They can cause symptoms such as swelling and inflammation. Treatment may include topical or oral antibiotics.

Experts classify bacterial skin infections as skin and soft tissue infections (SSTI) or acute bacterial skin and skin structure infections (ABSSSI).

This article details the types of bacterial skin infections and discusses symptoms, causes, treatment options, and more.

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Skin infections involving bacteria can affect the skin, underlying subcutaneous tissue, or muscles, ranging from superficial surface infections to severe necrotizing conditions.

SSTIs are infections that affect the skin or soft tissue. The Food and Drug Administration (FDA) previously categorized these as “complicated SSTI” and “uncomplicated SSTI.” More recently, the FDA has categorized bacterial skin infections as either SSTI or ABSSSI.


Examples of SSTI include:


ABSSSIs are more complex bacterial skin infections. A 2013 FDA release defines ABSSSI as the following:

The primary infections in SSTIs are Streptococcus and Staphylococcus species, including methicillin-resistant Staphylococcus aureus (MRSA).

According to the Centers for Disease Control and Prevention (CDC), around 33% of people carry S. aureus bacteria in their nose. Around 2 per 100 people carry MRSA. However, most people do not develop serious MRSA infections.

The CDC also reports that MRSA bloodstream infections decreased in healthcare settings by 17.1% each year between 2005–2012.

Learn more about MRSA.

Symptoms of bacterial skin infections may depend on the type of infection but can include:

It is best for a person with any of these symptoms to contact a doctor for a diagnosis. A doctor can order tests to confirm the cause of the symptoms and advise on suitable treatments.

Learn more about the symptoms of a bacterial infection.

Bacterial skin infections can develop when bacteria enter through the surface of the skin. For example, this can happen through a cut or a wound.

Bacteria can also enter the skin through surgical incisions. As a result, SSTIs are the most common healthcare-associated infections among people undergoing surgery.

A doctor may diagnose a bacterial skin infection through clinical signs and symptoms.

They may also order laboratory tests to confirm the type of infection. This involves either swabbing or removing a sample of the affected skin for examination under a microscope.

A doctor can advise which tests they order and what the person can expect.

Experts recommend that doctors manage infections such as impetigo, erysipelas, and cellulitis with topical antibiotics against Gram-positive bacteria. Doctors may also treat community-acquired MRSA with antibiotics.

Additionally, medical professionals may treat simple abscesses and boils by making a surgical incision and draining them of pus.

In some cases, doctors may treat severe bacterial skin infections in hospitals. A person may require oral or intravenous antibiotics.

Learn more about antibiotics.

A person can take steps to reduce the risk of bacterial skin infections. These can include:

  • washing their hands regularly
  • cleaning any cuts with soap and water
  • following their doctor’s guidelines for preventing skin infections, particularly if they are at an increased risk of infection

Guidelines recommend that medical staff take appropriate precautions to avoid bacterial skin infections in a hospital setting. Recommendations include ensuring that a person bathes or showers before surgery and that surgical teams clean their hands appropriately.

It is best for a person to contact their doctor for more advice on ways to prevent bacterial skin infections.

Bacterial skin infections comprise skin and soft tissue infections (SSTI) or acute bacterial skin and skin structure infections (ABSSSI). Symptoms can vary depending on the severity of the infection but can include inflammation, swelling, pain, and warmth.

Treatment for bacterial skin infections may involve topical medications to apply to the skin or oral antibiotics. For more severe conditions, doctors may administer antibiotics intravenously.

A person can help reduce the risk of bacterial skin infections. These include regularly washing hands and properly cleaning any cuts. It is best to contact a doctor for advice if a person has concerns about bacterial skin infections.